WARNE: Zach Duke is not a Specialist; Paul Molitor Knows This

Stereotypes happen for various reasons. Sometimes it’s lazy analysis, sometimes there’s a long pattern of player types that a guy gets lumped into and sometimes it’s something far more nefarious.

Sometimes those lines get blurred, like when Teddy Bridgewater or DeShone Kizer are anointed as running quarterbacks — both ran 40s in the 4.8-second range, which is by no means blazing — or guys like Robinson Cano are slapped with the label of being ‘lazy.’ While the intent of the person making those judgments is unclear, everyone draws their own conclusions there.

What we want to talk about today is far less dicey and far less socially controversial — and it’s the idea that Twins left-handed pitcher Zach Duke is only a specialist.

Pitchers with general profiles like Duke’s are a dime-a-dozen; he’s left-handed, not particularly young (sorry, Zach!) and rarely sees 90 mph with his fastball. In fact, that’s one thing that hasn’t changed about him no matter how he’s been used — his fastball has never averaged 90 mph. What’s remarkable is that he’s managed to stay at a career average of 88.3 mph according to Fangraphs but never even once in parts of 14 MLB seasons sneak over that mark, though he’s been as close as 89.7 mph twice.

With that profile comes the inevitable comps to other pitchers like him, and virtually all of them are what the baseball community call LOOGYs. That’s short for Left-Handed, One Out Guy, to belabor the point.

The Twins have had plenty of those types in recent years. Taylor Rogers hasn’t been used much like that in previous years, but in a deeper bullpen — such as this year’s Twins one — he might see a more lefty-heavy approach. Brian Duensing was also that type of pitcher, and other guys like that included Ryan O’Rourke, Buddy Boshers, Fernando Abad and to take it back a ways, guys like Ron Mahay and even Randy Flores apply.

But while it would be easy to lump Duke into that group, the stats don’t really bear it out. Fangraphs has a handy splits tool that lets us look at how a pitcher fares against lefties and righties based on a custom date range, and allows us to look at look at concrete data to form opinions.

Duke became a full-fledged reliever in 2014 with the Milwaukee Brewers, with his career on life support after a really, really tough 2013 split between the Nationals and Reds (6.03 ERA in 31.1 innings).

Since then, Duke has done the following:

Against LHH — .207/.290/.308 (.269 wOBA, 27.8 percent K rate)

Against RHH — .220/.325/.353 (.297 wOBA, 26.1 percent K rate)

These aren’t exactly small sample sizes either, as he’s faced 482 righties and 367 lefties over that stretch. Yet there seems to be angst from fans whenever manager Paul Molitor brings him into a spot to face righties.

“I’m kind of familiar with any situation that comes up. I feel like I have weapons to attack both”

It’s kind of a confusing dichotomy. If people want to say Duke hasn’t pitched that well this season and shouldn’t pitch big spots, that’s a totally reasonable thing to say. He’s allowed five earned runs in four innings and has walked six batters. Opposing batters are hitting just .188, but with a .458 on-base percentage. But to say he shouldn’t face right-handed hitters is just so strange considering he’s been adept at getting them out to this point as a reliever.

Comparisons like this can be hard to make, but here’s how some of his bullpen comrades have fared against righties while they’ve worked in relief in their careers:

Addison Reed – .236/.276/.392 (.298 wOBA)

Trevor Hildenberger – .250/.302/.436 (.317 wOBA)

Fernando Rodney – .212/.311/.323 (.286 wOBA)

Ryan Pressly – .231/.285/.384 (.289 wOBA)

Taylor Rogers – .288/.353/.435 (.336 wOBA)

Don’t get me wrong — it’s a fine bullpen. But if you think Duke isn’t going to be asked to get righties out with some regularity, that’s just not a reasonable proposition.

Duke is totally aware of the LOOGY perception, and also is pretty much willing to do whatever it takes to get guys out — right or left. That includes wacky arm angles, quick pitches or whatever else a person can think of.

“Obviously I have a lot of experience starting as well as relieving,” Duke said. “I’ve been asked to face both my whole career. I have weapons to attack lefties and righties. I’m comfortable with facing both. It’s not like I’ve only been a lefty guy; I started early in my career and was asked to get through lineups three or four times. I’m kind of familiar with any situation that comes up. I feel like I have weapons to attack both.”

His answer about what it was like to switch from starting to relieving is really, really in-depth, but also comes with a caveat that shows you just how seriously he takes himself.

“The toughest thing was finding a routine that gets me ready physically every day,” Duke said. “Then, managing the adrenaline spikes and letdowns. Coming through the biggest situations, the adrenaline gets up high. If you get through that, coming to the dugout is a big letdown, just from a physiological standpoint. That rush of emotions get you up so high, then you come down off that. Your body reacts in such a way that shuts everything down, so you have to find ways to keep that adrenaline spike up to keep yourself engaged in case you’re asked to go back out. That was kind of the toughest part for me, figuring out how to keep your level up to where if you’re asked to go back out, you can stay at a higher level.”

So why did he make some of the changes he did?

“Hitters showed me they were over all my other stuff,” he said with a laugh.

Good point.

Molitor enjoys having him in the bullpen because he won’t back down from a challenge.

“(Fernando) Rodney, Duke and (Addison) Reed, in particular, have made it clear to me, “Whatever you want, whenever you need me, if I’m available to throw, it doesn’t matter to me.” That’s a good feeling for a manager,” Molitor said earlier in the homestand.

In short, there are previous few lefties who throw FM college radio fastballs who get guys out on both sides of the plate, but Duke’s been one of those guys since moving to the bullpen. He may not have done it quite as well this year, but it’s too early to jump ship.

Warne covers the Minnesota Twins for Zone Coverage and is also the site's senior editor. He hosts the Midwest Swing podcast for the site as well. He and his wife Amanda live in the outer Twin Cities suburbs with their daughter, Harper.